I am not convinced that will cause either of the two Exceptions we saw. If you have the .class files in the wrong location you tend to get errors like class not found or wrong class name.
Are you sure about the Java versions? You will have problems if you use the Java7 JDK and the Java6 JRE together. If the Java7 JDK appears first in your System PATH, as described
here and
here, then you will only ever use Java7. If java -version returns 1.7.0_10, then you have probably set your PATH correctly.
As for the SQL exception: don’t know. Find the documentation (?Oracle) and see what ORA-0911 means.
Try to work out from the line numbers which query it was, or run every SQL query at the command line, rather than
via a Java front‑end, and see which produces an Exception. Show is the full query, characters like ã included.
I think this discussion would now fit better in our databases fora. Moving it.